The objective of this project is to further our understanding of the role played by signalling pheromones in the regulation of social behavior in rodents. In particular, we plan to explore maturational and experiential determinants of the responses by rodents to pheromones in five social contexts, namely: mating, maternal behavior, predatory behavior, feeding behavior, and withdrawal responses evoked by alarm signals. BIBLIOGRAPHIC REFERENCE: Carr, W.J., Yee, L., Gable, D., and Marasco, E. Olfactory recognition of conspecifics by domestic Norway rats. Journal of Comparative and Physiological Psychology. (Accepted for publication, November, 1975.), in press.